[GUI] replaced watchdog inconsistency icons

I am not an UX expert but those new icons should more comprehensible
than the old ones (which was worse). Suited for color blind users (ok =
blue, error = red).

Change-Id: I88b18f07039d69eb7bb62101ee57e671524e3584
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1185
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>